Spurt cap

ABSTRACT

A spurt cap for use with test tubes is provided. It is hollow, open bottomed and has top closure. A spring clip is attached to its bottom edge which clamps it over the test tube mouth. A transverse screen extends across its interior to slow down the movement of fluid spurting out of the tube.

United States Patent Johnston Larson Cooke Dowrie Krause Woods Morton Porter Nungester Primary Examiner-Donald F. Norton Attorney-Emest Peter Johnson 220/44(A) 220/44 A 215/38 220/44(A) 220mm 220/44(A) 215/38 22o/44x 215/38 ABSTRACT: A spurt cap for use with test tubes is provided. It is hollow, open bottomed and has top closure. A spring clip is attached to its bottom edge which clamps it over the test tube mouth. A transverse screen extends across its interior to slow down the movement of fluid spur-ting out of the tube.

SPURT CAP This invention relates to a spurt cap for use with a test tube. The cap serves to downwardly redirect material which occasionally spurts from the mouth of a test tube when the said material is being heated or is reacting therein.

When material is being heated or is reacting within a test tube, it occasionally spurts out, sometimes with considerable force. Such materials can be very hot and/or corrosive in nature. As a result, serious injuries sometimes occur in laboratories when nearby persons are struck by the material; this is particularly so when it splashes on the face or in the eyes. Very often the material will contact the clothes of theadjacent person and can, in due course, ruin them. To reduce these problems, laboratory designers for such institutions as schools and universities have taken to spacing workers apart a substantial distance and have required the wearing of safety glasses and laboratory coats. This has, of course, increased operating costs.

There is therefore a need for a low cost device which can be conveniently used with a test tube to deflect spurting material and redirect it in a manner whereby it will be harmless.

SUMMARY OF THE INVENTION The present invention provides such a device. In its simplest fomr it comprises a hollow, open-bottomed cap, having top closure, which carries means for disengageably securing it over the mouth of a test tube having an outwardly protruding lip. The cap provides a containing surface or closure which acts to deflect material spurting upwardly out of the tube mouth and redirects it downwardly whereby it may reenter the tube or be discharged through an annular opening-defined between the bottom portion of the cap sidewall and the upper rim of the test tube.

According to the preferred embodiment, a portion of the cap sidewall will extend downwardly to provide a lug. The lug will be formed of slightly flexible material. A spring clip is mounted on the lug engagement with the test tube. Material slowing means, such as one or more fine screens, may be disposed within the upwardly extending cavity defined by the sidewall and top closure of the cap. The threads of the screen, which extend across the cavity in the path of the spurting material, will slow its movement.

DRAWINGS The invention is illustrated in the following drawings in which:

FIG. 1 is a side view, partly in section, of a cap in accordance with the invention, shown secured to a test tube;

FIG. 2 is a bottom plan view of the cap;

FIG. 3 is a perspective view of the cap.

DETAILED DESCRIPTION In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.

The invention includes a cap 1, having a sidewall 2 and top closure 3, defining cavity 4. A flexible lug 5 projects downwardly from sidewall 2 and a horizontal spring clip 6, for clamping onto test tube 7, is mounted thereon. A plurality of upwardly spaced screens 8, for slowing down the rate of movement of material spurting from tube 7, are fixed within cavity 4 in a position substantially transverse to the longitudinal axis of the tube 7.

In greater detail, cap 1 is illustrated having an upwardly tapered sidewall 2, of circular cross section and a horizontal top closure 3. It will, of course, be obvious that cap 1 may take a number of shapes, such as a semispherical shape. It is necessary only that an upwardly extending cavity 4, which is closed off at its upper end, be defined.

The cap will preferably be constructed of light, sturdy, slightly flexible, inexpensive, corrosion resistant, material. A number of plastics, for'example, are suitable and the choice of one will not involve any difi'rculty.

Means for snapping cap onto 1 onto test tube 7 to position the cap in the operative position are provided. By the operative position is meant that the cavity 4 substantially overlies the test tube lip. Such means preferably should be flexibly mounted in order that the cap may be easily removed from the test tube with one hand. For example, as illustrated, a spring steel clip 6 having spaced, forwardly projecting resilient arms may be mounted on aslightly flexible lug 5 in spaced relation below the lower edge of sidewall 2. The forward ends of the arms define a gap between them whereby they are adapted to be snapped on or off the tube. Lug 5 is shown comprising an integral extension of sidewall 2. It is desirable that the lip 8 of sidewall 2 be disposed flush with or below the mouth of test tube 7. In other words, the lip 8 should be in close proximity to the said mouth. This will, of course, prevent spurting material from bypassing cap 1. By providing a flexibly mounted spring clip 6, it will be seen that the lip 8 may be lifted well clear of the rim of test tube 7 when cap 1 is to be removed. This will prevent binding between the lip 8 and test tube 7.

There are a number of equivalents which could be substituted for the particular means for mounting the spring clip which is described. For example, the spring clip could be mounted on a spring steel shank secured to sidewall 2. When designing a desirable mounting, it should be kept in mind that the sidewall 2 should extend downwardly far enough whereby spurting material cannot bypass cap cavity 4 and that the securing means should be flexibly mounted so that cap 1 may be removed without binding.

Means are provided within cavity 4 to slow down the speed of movement of spurting material. As shown, such means may comprise a plurality of spaced screens 9 which are disposed transverse to the line of travel which escaping material would take. The screens may be set so that each succeeding screen is out of phase with the preceding one in order that maximum contact between the fluid and the screen crommembers is effected. The mesh of screens 9 should be large enough whereby the material may pass through the apertures defined.

It will be appreciated that other material slowing means may be substituted for screens 9. As one example, a plurality of rigid nonintersecting fingers may be provided to extend across the path of the escaping fluid.

It is desirable that tube 7 and cap I form a reasonably solid unit. This may be achieved by mounting the lowest screen 9A in a position wherein rim 8 of tube 7 will press against it when the cap is in place.

I claim:

1. A spurt cap, adapted to be detachably secured to a test tube having a lip, comprising:

an open-buttomed cap, having a sidewall and top closure,

defining a cavity;

a flexible lug comprised of a downwardly directed extension of a portion of the rear sidewall; and

a horizontal spring clip mounted on the lug in spaced relation below the lower edge of the sidewall, said clip having spaced, forwardly projecting, resilient arms defining a gap between their forward ends whereby they are adapted to be snapped onto a test tube to position the cap over the mouth of the test tube whereby the cavity substantially overlies the test tube lip.

2. In combination:

a test tube having an outwardly protruding lip;

a spurt cap, detachably secured to the test tube, comprising:

an open-bottomed cap, having a sidewall and top closure,

defining a cavity of greater diameter than the diameter of the test tube lip;

a flexible lug comprising of a downwardly directed extension of a portion of the rear sidewall;

a horizontal spring clip mounted on the lug in spaced relation below the lower edge of the sidewall, said claim clip having spaced, forwardly projecting resilient arms which embrace the test tube immediately below the test tube lip, said clip being adapted to be snapped on or off the test tube;

the test tube whereby the cavity substantially overlies the test tube lip. 3. The spurt cap of claim 1 wherein: a plurality of thin elongate members are attached to the wall of the spurt cap'and exsaid spring clip and lug being so constructed as to position 5 at least P way across the ythe the cap in the operative position over the mouth of 

1. A spurt cap, adapted to be detachably secured to a test tube having a lip, comprising: an open-buttomed cap, having a sidewall and top closure, defining a cavity; a flexible lug comprised of a downwardly directed extension of a portion of the rear sidewall; and a horizontal spring clip mounteD on the lug in spaced relation below the lower edge of the sidewall, said clip having spaced, forwardly projecting, resilient arms defining a gap between their forward ends whereby they are adapted to be snapped onto a test tube to position the cap over the mouth of the test tube whereby the cavity substantially overlies the test tube lip.
 2. In combination: a test tube having an outwardly protruding lip; a spurt cap, detachably secured to the test tube, comprising: an open-bottomed cap, having a sidewall and top closure, defining a cavity of greater diameter than the diameter of the test tube lip; a flexible lug comprising of a downwardly directed extension of a portion of the rear sidewall; a horizontal spring clip mounted on the lug in spaced relation below the lower edge of the sidewall, said claim clip having spaced, forwardly projecting resilient arms which embrace the test tube immediately below the test tube lip, said clip being adapted to be snapped on or off the test tube; said spring clip and lug being so constructed as to position the the cap in the operative position over the mouth of the test tube whereby the cavity substantially overlies the test tube lip.
 3. The spurt cap of claim 1 wherein: a plurality of thin elongate members are attached to the wall of the spurt cap and extend at least part way across the cavity. 